Greater Sandhill Crane

Grus canadensis

One of the most notable birds
on the Refuge is the long necked, long legged, Greater Sandhill Crane.
This largest of the sandhill crane subspecies stands up to 4 feet tall with a
wingspan of over 6 feet. Birds of that
size stand out even in the vast expanses of the Nevada landscape. Its
grey-brown body and white face are contrasted with a red forehead. These
very vocal birds have an unmistakable honk and gurgling call and engage in intricate
“dance” moves for pair bonding.

Greater Sandhill Cranes migrate
back to the Refuge in March after a sunny winter in Arizona. Upon arrival,
pairs quickly establish nesting territories. These crane pairs defend a
large area of up to 400 acres which typically includes wet meadows, grasslands,
and shallow wetlands. It is believed
that sandhill cranes mate for life and both parents share in the responsibility
for raising their 1-2 young, or colts, per year. Limited suitable nesting
habitat and predation of eggs and colts limits population growth for
cranes. In a typical year about 20 pairs of cranes nest on the Refuge,
hatching 9 colts and fledging 1-2 per year. In fall, the cranes begin
their migration southward and may be seen in flocks, “staging”, before they
leave.

Ruby Valley is well
suited to Greater Sandhill Cranes and has probably been a nesting ground since
the last glacial period. However, population declines of all crane
subspecies occurred during the latter 1800s.
Declines were countered with hunting bans and sandhill crane populations
have stabilized since the 1980s. There are two separate populations of
Greater Sandhill Cranes. The Lower Colorado River Valley Population,
which includes the Ruby Valley birds, is the smaller, averaging 2,442 birds
between 2009 and 2011. Nevada Department of Wildlife lists the Greater
Sandhill Crane as a Species of Conservation Priority in their Wildlife Action
Plan and the Bureau of Land Management lists the birds as a Sensitive Species.

Turn to the next page to learn
more about threats to Greater Sandhill Cranes and how the Refuge can help.

Threats

Sandhill crane populations are controlled, in part, by home
territory size of crane pairs within a limited area of suitable habitat.
This, coupled with a low annual colt recruitment rate, explains why the
Refuge has had a stable number of breeding pairs over the last several decades.

Grazing and prescribed fire are used to invigorate decadent vegetation
in meadows, creating better foraging conditions and increased
productivity. However, these tools must
be used in a manner that creates a mosaic across the landscape that includes
tall, dense vegetation for nest concealment and cover for colts which are
unable to fly. Additionally, dense vegetation may support abundant small
mammal populations which decrease predators’ need to seek crane eggs and colts
as prey.

Predation of crane eggs by ravens and predation of colts and eggs
by coyotes can be significant. It is
possible that these predators have reached unnaturally high population levels
due to human-caused habitat changes. Disturbance by humans during nesting
also may lead to nest abandonment or increased predation of eggs or colts while
the crane parents are away.

Invasive plant infestations cause several changes to native plant
communities which could negatively impact sandhill cranes. Invasive
plants may be unpalatable or toxic and displace plants which are desirable to
cranes as food in the form of seeds or tubers. They can alter insect,
reptile, or small mammal communities which provide quality forage for
cranes. Dense infestations of some invasive plant species could be
unusable by colts, thus reducing the overall available habitat within a crane
pair’s territory.

Greater Sandhill Cranes are a migratory species so the wellbeing
of the Ruby Valley population is linked to the management of surrounding lands
and of all the lands the birds utilize along the migration path. The
Refuge can play an important role by:

What We Do

Relict Dace, the only native species of fish at Ruby Lake, has reduced and hybridized populations due to introduction of several non-native species. A project is underway to preserve the biological integrity of the Relict Dace.